Fire barrier box for membrane penetrations

ABSTRACT

A fire barrier box for placement within a fixture membrane in a fire barrier wall provides a metallic side panel box of multiple box sides, each side having a slot, and a selectively attached back panel. An intumescent liner attaches to the inner side panel walls and to the interior surface of the back panel. When a fixture is received within the side panel box, the intumescent liner, and the slots cooperatively receive fixture supply lines enabling their connection with the fixture. The selective attachment of the back panel occurs once rear access to the side panel box interior is no longer required. The completed fire barrier box attaches to the stud framing, maintaining the rating protection of the fire barrier wall.

RELATED APPLICATIONS

The present application claims the benefit of priority under 35 USC § 119(e) to U.S. Provisional Application No. 62/486,249 filed on Apr. 17, 2017, which is incorporated by reference herein for all that it contains.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to thermal barriers and, more particularly, to fire resisting thermal barriers. More specifically, the present invention relates to fixture-receiving fire barrier boxes placed within membrane penetrations in a fire barrier wall.

Description of the Related Art

As part of the passive fire protection system for a building, a fire barrier wall acts to prevent or delay the spread of fire. Building codes require a specified fire resistance rating for the interior walls and ceilings of commercial buildings, depending upon their location and the nature of their use within the commercial structure. Frequently fire ratings are specified based upon duration (for example a 1-hour minimum resistance) under standardized test conditions.

Most commercial buildings have recessed fixtures spaced along the corridors, such as fire extinguisher cabinets, fire hose cabinets, and electrical panels, and in demising walls, such as wall safes, eye wash stations, utility controllers, dryer vent boxes, shower valves, plumbing feeds, and speaker boxes. At such locations, the breach in the fire-resistant material is termed a “membrane penetration.” Upon completion of the wall or corridor, building codes require compliance with the required fire resistance rating. Any breaches resulting from installation of recessed fixtures cannot reduce the required fire rating of the wall or partition.

Shower valves present a difficult membrane penetration to address. Besides the complexities of a moving valve, their construction includes many supply lines, and often a non-metallic escutcheon plate. Creating a fire barrier for a shower valve penetration is difficult enough in new construction; trying to apply existing solutions in a retrofit application is not economically feasible.

SUMMARY OF THE INVENTION

The present invention provides a metallic box construction having an open front and a removable back. The inside surfaces of all four sides of the metallic box and the removable back are covered by an adhering tested and listed fire blanket or mat, such as 3M′ Product ID I-10, (3M Fire Protection Products, www.3m.com/firestop). A central slot formed in each of the four metallic side panels of the metallic box permits installation of the box over existing supply lines. The removable back enables the use of the box for retrofit applications.

One aspect of the embodiments disclosed herein is a fire barrier box configured for receipt within a fixture membrane penetration in a fire barrier wall. Comprising a side panel box having inner side walls defining an interior space adapted to receive the fixture of the fixture membrane penetration. Wherein said side panel box is metallic and wherein said side panel box comprises a plurality of box sides, each of the plurality of box sides having a slot formed therein. An intumescent liner attached to and extending over the entirety of the inner side walls of the side panel box. Wherein the intumescent liner and at least one of the slots formed in each of the plurality of box sides are adapted to cooperatively receive in a thermally-sealing manner a fixture supply line extending from a location outside of the side panel box to a connection with a fixture located within the interior space of the side panel box. A back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space and an interior surface of the back panel; and an intumescent back panel piece attached to and covering the interior surface of the back panel.

Another aspect in accordance with the embodiments disclosed herein is a fire barrier box comprising a side panel box defining an interior space adapted to receive a fixture, wherein the side panel box comprises a plurality of box sides. Each of said plurality of box sides having an inner side wall and at least one of said plurality of box sides having a slot formed therein. An intumescent liner attached to and extending over each of the inner side walls, wherein the intumescent liner and the said at least one of the plurality of box sides having the slot formed therein are adapted to cooperatively receive a fixture supply line extending into the interior space; and a back panel having an interior surface formed thereon, the back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space, wherein an intumescent mat is attached to and overlies an interior surface of the back panel.

A still further aspect in accordance with the embodiments disclosed herein is a fire barrier box comprising a side panel box for being received within a fixture membrane penetration in a fire barrier wall. The side panel box having an inner side wall that defines an interior space adapted to receive a fixture, wherein the inner side wall has at least one slot formed therein. An intumescent liner attached to and extending about a circumference of the inner side wall, the intumescent liner and the at least one slot adapted to cooperatively receive a fixture supply line extending into the interior space and establishing a connection with the fixture. A back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space and an interior surface of the back panel; and an intumescent back panel piece attached to and covering the interior surface of the back panel.

These and other objects, aspects, and features of the present invention will be better understood from the following description of embodiments when read in conjunction with the appended drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other aspects of this disclosure are described in detail below in connection with the accompanying drawing figures in which:

FIG. 1 illustrates a partial perspective view of the fire barrier box disclosed herein receiving a shower valve and associated plumbing (shown in phantom), the fire barrier box installed within a wall and attached to the stud framing in a fixture membrane penetration within a fire barrier wall;

FIG. 2 is an exploded perspective view of the fire barrier box of FIG. 1;

FIG. 3 is a perspective view of the side panel box of the fire barrier box of FIG. 1;

FIG. 4 is a top plan view of the side panel box of FIG. 3;

FIG. 5 is a side elevation view of a first side of the panel box of FIGS. 3 and 4;

FIG. 6 is a side elevation view, with a portion shown in phantom, of a second side of the panel box of FIGS. 3-5;

FIG. 7 is a perspective view of the back panel of the fire barrier box of FIG. 1;

FIG. 8 is a top plan view of the back panel of FIG. 7;

FIG. 9 is a side elevation view of the back panel of FIGS. 7 and 8;

FIG. 10 is a perspective view of the side panel box of FIGS. 3-6 and the attached back panel of FIGS. 7-9;

FIG. 11 is a top plan view of the side panel box and attached back panel of FIG. 10;

FIG. 12 is a side elevation view of a first side of the side panel box and attached back panel of FIGS. 10 and 11;

FIG. 13 is a side elevation view of a second side of the side panel box and attached back panel of FIGS. 10-12;

FIG. 14 is a perspective view of the fire barrier box of FIG. 1; and

FIG. 15 is a cross-sectional view of the fire barrier box of FIG. 14 taken along line 15-15 of FIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The fire barrier insert for membrane penetrations is disclosed herein with respect to exemplary embodiments. The embodiments are disclosed for illustration of the fire barrier box for membrane penetrations and a manner of making use of such barrier box and are not limiting except as defined in the appended claims.

Reference is now made to the drawings wherein like structures refer to like parts throughout. FIG. 1 depicts a fixture membrane penetration 10 within a fire barrier wall 12, with a fire barrier box 16 installed within the penetration, the fire barrier box including an inner intumescent mat liner 18 extending over the entirety of the inner side walls and a back panel 22, also lined with an intumescent mat. A shower valve 24 is shown within the fire barrier box 16, with a plurality of attached water supply lines 26 and line connectors 28. The shower valve 24 and associated plumbing hardware is presented as an example of a manner of using the present invention. The present invention is not limited to use with any specific fixtures, fixture supply lines, or fixture membrane penetrations.

In most commercial buildings the fire barrier wall 12 is constructed using drywall panels attached to a framework of either metal or wood studs. Although not shown in FIG. 1, a pair of adjacent studs supports the horizontally-extending pair of steel channels 34 a, 34 b.

The fire barrier box 16 is mounted in the wall using a pair of box flanges 38 which are placed flush against the pair of steel channels 34 a, 34 b. A pair of fasteners 44 attach the box flanges to the steel channels. The back panel 22 is attached once rear access to the shower valve or other fixture is no longer needed.

The component parts of the fire barrier box are shown in FIG. 2, a side panel box 48 having a plurality of box sides 50 receives a plurality of intumescent mat side panel pieces 52, each of which attaches to an inner side wall 54 of a separate box side. An intumescent mat back panel piece 56 attaches to an interior surface 58 of the back panel 22, which is then attached to the side panel box 48 to provide a closed bottom and complete the fire barrier box 16.

Shown in greater detail in FIGS. 3-6, the side panel box is preferably fabricated using galvanized sheet metal of minimum 0.035-inch thickness. The sheet metal is formed in a four-panel length, which is bent to form a rectangle of the four box sides 50, with an end attachment tab 62 spot-welded to the initial section of the first panel, as shown in FIG. 3, forming the side panel box. The upper lateral edges of each of the four panels are bent outwardly, forming the box flanges 38.

Each of the box panels has an opening formed therein, shown as a central slot 64 in the drawings. Although disclosed in the context of shower valve installations, the present invention is applicable for use with other appliances or fixtures, and when mounted within the barrier box such other devices may require the insertion of different supply lines and the making of different connections. When so used, the openings formed in the box panels are positioned and formed to accommodate such device connection requirements.

The back panel 22, shown in FIGS. 7-9, is preferably also formed using galvanized sheet metal. The lateral edges of a rectangular sheet of proper dimensions are bent up, forming the pan-shape seen in FIG. 7, having the interior surface 58 and up-raised sides 68. A plurality of fastener apertures 74 are formed in the up-raised sides and located adjacent to one-another at each corner of the back panel. Upon attachment, the back panel defines a closed bottom to the interior space of the side panel box, as shown in FIGS. 10-13. Fasteners, such a metal screws, are received in the fastener apertures and used to secure the back panel to the side panel box, with the up-raised sides of the back panel received by lower outside surfaces of the side panel box. In a presently preferred embodiment, attachment of the back panel to the side panel box requires at least two metal screws per side (metal screws are not shown in the drawings).

Although such attachment is preferably delayed until rear access to the shower valve or other appliance is no longer required, the fixture is not part of the present invention and FIGS. 14 and 15 show the complete fire barrier box with the back panel attached and all intumescent mats likewise attached to their respective panel surfaces.

A plurality of supply line apertures 78 are formed in each of the intumescent mats 52 at that portion of the mat that overlies the central slot 64. In this manner the intumescent liner and the central slot cooperatively receive, in a thermally-sealing manner, a fixture supply line, enabling its connection to and with the fixture. As noted previously, the supply line requirements of a fixture will determine the need and location for such supply line apertures. Those apertures shown in FIGS. 14 and 15 are appropriate for shower valves, where water supply lines extend through each of the panels in the side panel box.

By way of example and not limitation, the following narrative provides general guidance regarding a presently preferred manner of assembly and use of the fire barrier box of the present invention. For use with a shower valve, it is presently contemplated to provide a 10-inch by 10-inch box of 3.25-inch depth, with central slots measuring 2.75 inches in length and 1 inch in width. It is also contemplated to offer the metallic box in other dimensions of 3.25-inch depth, including 6-inch by 6-inch, 7-inch by 7-inch, 7-inch by 8-inch, 8-inch by 8-inch, and such other custom sizes and depths as needed. Where dimensions are provided, they are intended as illustrative, and not limiting on the scope of the present invention.

FIG. 2 shows the attachment of the intumescent mat pieces to the side panels and to the back panel. The intumescent mat is preferably 3/16 inch in thickness, and a presently preferred mat is I-10 mat manufactured by 3M® Company, Minneapolis, Minn. (www.3m.com). Attachment to the panels is preferably with an adhesive such as 3M® Super 77® or Super 90 spray adhesives, manufactured by 3M® Company. Two intumescent liner mats are sized to be the same length as that of the side panels, and two are shorter, enabling them to fit between the longer lengths when attached to opposing side panels.

The width of each side panel piece is selected to result in a ⅛-inch recess from the base of each side panel. Upon attachment of the back panel, the inner intumescent 3/16-inch back panel mat presses against the recessed edges of the side panel mats, obtaining a tighter, compressed fit. Under a fire condition, the intumescent mat expands, sealing the inside surfaces of the metallic box, forming a fire barrier across the membrane penetration.

FIG. 1 shows the present fire barrier box invention as installed in a shower valve membrane penetration, which may be for new construction or to retrofit such membrane penetrations in a previously-constructed building. For either construction type, before mounting the side panel box in the wall, identification is made of which side panels require openings to permit supply line penetration of the intumescent mat panel where it overlies the central slot. Where openings are required, an aperture is formed in each such mat, such as by drilling or by cutting an X-shape in the mat material, the aperture preferably is formed having the same inner diameter as the outer diameter of the supply line.

The fire barrier box may be used in both metal and wood stud construction, with both metallic and PEX (cross-linked polyethylene) supply lines. In new construction, after forming the side panel apertures, the side panel box is mounted in the wall with the box flanges flush with the framing members.

Insertion of each supply line follows, through a separate aperture and into the box interior. Connections are made between the shower valve and each of the supply lines. The present invention is not limited to shower valve installations and other appliances or fixtures mounted within the barrier box may require the insertion of different supply lines and the making of different connections.

A retrofit to surround an existing shower valve (or other appliance) first requires forming a slit in the mat overlying the central slot, from the bottom of the aperture to the base edge of the mat. The slit in the mat enables passage of an existing supply line through the mat until reception of the line within the aperture. Such supply line passage occurs by placement of the side panel box over and around the shower valve (or other appliance) and pressing inwardly on the side panel box until each of the supply lines are moved through the slits and into each of the mat apertures. Final side panel box positioning places the front box flanges flush with the framing members.

Attachment of the back panel to the box, preferably using at least two metal screws per side (either top/bottom or on both sides), proceeds once rear access to the shower valve or other appliance is no longer needed. The attachment may occur upon completion of the retrofit box placement over the shower valve or appliance. In other instances, installation steps may be easier when front and back access is available, and back panel attachment is delayed until those steps are completed. As one example, when installing a shower valve rear access may help the process of water line connection. Once that is completed, back panel attachment occurs.

With the fire barrier box attached to the stud framing and the back panel attached, completing the box structure, it is presently preferred to apply a caulking compound around the supply line/aperture interface as well as completely covering the back of the intumescent mat material exposed by the central slot opening. A presently preferred caulking compound is 3M™ Fire Barrier CP25WB+, which is an intumescent material.

The materials covering the open front of the fire barrier box are typically gypsum board over the outer portions away from the shower valve, with a water-proof tile overlay, and an escutcheon plate covering the center area immediately around the valve stem. A shower valve control handle connects to the valve through a central opening formed in the escutcheon plate. The control handle enables user operation of the shower valve.

The materials covering the barrier box opening are not part of the fire barrier, which is provided by the metallic box and intumescent mat construction. Should a fire occur within the space protected by the fire barrier wall, the fire barrier box within the membrane penetration maintains the rating protection of the fire barrier wall—with the wall protected from fire on either side.

On the “room side” of the wall, the open side of the barrier box (covered as detailed above with gypsum board, tile—usually, and an escutcheon plate) will be exposed to the fire. The heat will travel into the barrier box, seeking to transfer heat to the back side of the next-adjacent wall. The heat transferred into the box will activate the intumescent mat, which (greatly) expands upon exposure to the fire heat, further sealing the inside surfaces of the barrier box. The metal box and expanded mat both act to contain the heat/resisting the heat transfer to the back of the next drywall. This containment delays the heat degradation of the drywall on the opposite side of the Fire Barrier wall, maintaining the fire barrier rating of the wall, including that portion overlying the fixture membrane penetration.

On the “back side” of the wall (the side of the next-adjacent wall without the membrane penetration), a fire burning through the gypsum drywall of the back, adjacent wall would, with only a shower fixture present, burn through that opening, failing the wall barrier test requirements. With the fire barrier box installed, heat transfer to the back panel of the fire barrier box is impaired, both by the metallic box structure and by the fire heat-expanded 3/16-inch intumescent I-10 mat. The mat and intumescent caulking both expand to seal any gaps between the metallic box and the supply lines, denying heat entry into the unprotected shower valve area.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all the matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 

What is claimed is:
 1. A fire barrier box configured for receipt within a fixture membrane penetration in a fire barrier wall, comprising: a side panel box having inner side walls defining an interior space adapted to receive the fixture of the fixture membrane penetration, wherein said side panel box is metallic and wherein said side panel box comprises a plurality of box sides, each of the plurality of box sides having a slot formed therein; an intumescent liner attached to and extending over an entirety of the inner side walls of the side panel box, wherein the intumescent liner and at least one of the slots formed in each of the plurality of box sides are adapted to cooperatively receive in a thermally-sealing manner a fixture supply line extending from a location outside of the side panel box to a connection with a fixture located within the interior space; a back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space and an interior surface of the back panel; and an intumescent back panel piece attached to and covering the interior surface of the back panel.
 2. The fire barrier box of claim 1, wherein said side panel box is rectangular and comprises four box sides.
 3. The fire barrier box of claim 2, wherein the intumescent liner and each of the slots in the four box sides are adapted to cooperatively receive a separate fixture supply line.
 4. The fire barrier box of claim 2, wherein the back panel is adapted to attach to the side panel box after receipt of the fixture within the interior space of the side panel box.
 5. The fire barrier box of claim 4, wherein the back panel is adapted to attach to the side panel box after completion of any connections between the fixture and one or more fixture supply lines.
 6. The fire barrier box of claim 4, wherein the back panel is adapted to attach to the side panel box after receipt of the side panel box over the fixture and connected supply lines in a retrofit installation.
 7. The fire barrier box of claim 1, wherein a box flange extends from and along a front edge of each of the plurality of box sides, and wherein at least one of the box flanges is adapted for attachment to a steel channel support extending within a fire barrier wall.
 8. The fire barrier box of claim 7, wherein a pair of box flanges are adapted for attachment to a pair of steel channel supports extending within the fire barrier wall.
 9. A fire barrier box comprising: a side panel box defining an interior space adapted to receive a fixture, wherein the side panel box comprises a plurality of box sides, each of said plurality of box sides having an inner side wall and at least one of said plurality of box sides having a slot formed therein; an intumescent liner attached to and extending over each of the inner side walls, wherein the intumescent liner and the said at least one of the plurality of box sides having the slot formed therein are adapted to cooperatively receive a fixture supply line extending into the interior space; and a back panel having an interior surface formed thereon, the back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space, wherein an intumescent mat is attached to and overlies an interior surface of the back panel.
 10. The fire barrier box of claim 9, wherein the side panel box comprises four box sides, and wherein each of the four box sides is adapted to cooperatively receive a separate fixture supply line.
 11. A fire barrier box comprising: a side panel box for being received within a fixture membrane penetration in a fire barrier wall, the side panel box having an inner side wall that defines an interior space adapted to receive a fixture, wherein the inner side wall has at least one slot formed therein; an intumescent liner attached to and extending about a circumference of the inner side wall, the intumescent liner and the at least one slot adapted to cooperatively receive a fixture supply line extending into the interior space and establishing a connection with the fixture; a back panel selectively attached to the side panel box in a manner defining a closed bottom to the interior space and an interior surface of the back panel; and an intumescent back panel piece attached to and covering the interior surface of the back panel.
 12. The fire barrier box of claim 11, wherein said side panel box is rectangular and comprises four box sides.
 13. The fire barrier box of claim 12, wherein the intumescent liner and each of the slots in the four box sides are adapted to cooperatively receive a separate fixture supply line.
 14. The fire barrier box of claim 12, wherein the back panel is adapted to attach to the side panel box after receipt of the fixture within the interior space.
 15. The fire barrier box of claim 14, wherein the back panel is adapted to attach to the side panel box after completion of any connections between the fixture and one or more fixture supply lines.
 16. The fire barrier box of claim 14, wherein the back panel is adapted to attach to the side panel box after receipt of the side panel box over the fixture and connected supply lines in a retrofit installation.
 17. The fire barrier box of claim 12, wherein a box flange extends from and along a front edge of each of the four box sides, and wherein at least one of the box flanges is adapted for attachment to a steel channel support extending within the fire barrier wall.
 18. The fire barrier box of claim 17, wherein a pair of box flanges are adapted for attachment to a pair of steel channel supports extending within a fire barrier wall. 